Housing for venetian blind operating mechanism



Jan. 16, 1940. F. E. LAWSON 2,187,458

HOUSING FOR VENETIAN BLIND OPERATING MECHANISM Original Filed May 7, 1937 3 Sheets-Sheet l g gg iii i i i wllllrlllll'. nrlllllulh Jan. 16, 1940. F. E. LAWSON 2,187,458

HOUSING FOR VENETIAN BLIND OPERATING MECHANISM Original Filed May 7, 1937 3 Sheets-Sheet 2 Jan. 16, 1940. I F. E. LAWSON I I 2,187,458

HOUSING FOR VENETIAN BLIND OPERATING MECHANISM Original Filed May- '7, 1937 3 Sheets-Sheet 3 1 11/ 1 I I 111/ 1 I 111 1 Patented Jan. 16, 1940 HOUSING FOIL VENETIAN BLIND OPERATING MECHANISM Fred 1:. lama, Philadelphia, Pa.

Original May I, 1937, Serial No. Divided and this application March 3,

1939, Serial No. 259,842

3Glaims.

This application is a division of my copending application, Serial No. 141,225, filed May '1, 1937, now Patent Number 2,149,301, March '1, 1939.

The present invention relates in general to a Venetian blind and is more particularly concerned with the details of construction of such a blind, whereby simplicity of construction is secured and'manipulation of the blind is facilitated.

i The primary object of the herein described invention is to provide a manually operable drum and flexible connector between the drum and the bottom rail of the blind for raising and lowls ering the slats 'of the blind.

to'an improved housing structure for the elements of the blind operating mechanism, which will enable the use of a standard preformed blank of such construction that it may be utilized for 'cflecting housings which are adapted for either right or left hand mounting, as desired.

Other features oi the present invention will more fully appear from the following detailed description taken in connection with the accom- -panying drawings which illustrate several embodiments thereof, and in which:

Fig. 1 is a view in elevation of a Venetian blind assembly embodying one iorm of the herein dey scribed invention; so Fig. 2 is a sectional view of the same, taken substantially on the line 2-2 of Figure 1;

Fig. 3 is an enlarged fragmentary sectional view through one side of the associated window frame, showing constructional details of the blind 5; raising and lowering mechanism;

Fig. 4 is an enlarged section taken substantially on line l-- of Fig. 1;

Fig.- 5 is an enlarged sectional view taken substantially on line 5-5 of Fig. 3;

441 Fig. 6 is a side view of a modified form of raising and lowering mechanism, showing itsassociation with a slat guide member:

Fig. 7 is a rear view of the same attached to a window frame; r 5 Fig. 8 is'a iragmentary sectional plan view of the samei Fig. 9*.is a sectional view taken through the housing of the raising and lowering mechanism showing the operative relationship of the instru- .mentalities therein; taken substantially on line 9-9 01 Fig. I, the slat guide member being removed;

Fig. 10 is a transverse sectional the same, taken substantially on line "-8! of The present invention more particularly relates view through Fig. 11 is a plan view of a standard blank which may be utilized for forming right or leit hand mountable housings for the raising and lowering mechanism;

Fig. 12 is a detail view showing the construction 01' cover plates for utilization with said housings;

Fig. 13 is a transverse sectional view showing 'the details of another modified form of reel mechanism; and

' Fig. 14 is an enlarged fragmentary sectional view 0! the same, taken substantially on line "-1" of Figure 13, to show the details of its latching mechanism.

As shown on the drawings:

,The numeral 6 indicates a window frame to which my improved blind is applied. It will be understood that the frame is provided with the usual sash but this has been omitted for conthe frame is a guide rail comprising a pair of strips 1, spaced apart to form a tape passage 8 and a facing strip 9. The latter strip is provided with a 'guideway preferably lined with a metal channel bar Ill. Secured to the other side of the frame is a second guide rail ll similar in all respects to the rail just described except that the tape passage 8 may, if desired, be omitted. Connecting the upper ends of the two guide rails is a rail ll having formed therein a tape passa e l2.

- The tilt bar it is removably supported by a pair of hangers l3 and II, the latter being provided ve'nience oi illustration. Secured to one side of with the usual gearing and operating cord II for controlling the position of the bar. These hangers may be of any usual and well-known construction and, therefore, need not be described in detail. The ladder' tapes Ii are each secured to the tilt bar by a clamp H which may be of any desired construction. The slats 20 rest freely on the cross members 2| or the ladder tapes with out any connection thereto. They are provided at each end with the usual trunnions 22 projecting into the channel bars ill. The fact that the slats are not attached to the tapes permits 01 their quick and easy removal and also permits relativemovement between the slats and thetapes which, together with the clamping of the tapes along the center line of the tilt bar, insures light tight closure of the slats when the tilt is moved to its extreme position in either direction.

The ends of the lift bar 23 extend into the channel II and have secured to them a pair of thin metal tapes 24 and 2!. The tape 20 era tends upwardly through the channel ll of the rail Ii directly behind the ends of the slab trumtop of the channel and thence through the channel l2 in the rail II to the opposite side of the frame and over a roller 21. The tape passes upwardly through the channel I in the strip 3 and also passes over the roller 21. The two tapes 24 and 25, after passing over the roller 21, are connected to a tape 28 (which may be a continuation of one of them). Tape 28 passes downwardly through the tape passage 8 to a roller 23, being twisted through an angle of 90 degrees during its passage. After passing around the roller 23, the tape enters a casing 30 and is se-' cured to a winding drum or reel 3| mounted therein.

In its passage to roller 23 the tape 28 passes behind a clutch block 32 having pins 33 movable in inclined slots 34 in a bracket 35 secured in the tape passage 8. A spring 36 normally forces the block upwardly to clamp the tape. The tape is thus free to move downwardly but is locked .against upward movement until the block is released. Bearing upon the upper end of the block is one end of a bell-crank lever 31, the other end of which is pivoted to the stem of a push-button 38, normally held in forward. position by a coil spring 33 surrounding its stem. The drum 3| rotates freely on a shaft 43 provided at its outer end with a handle 4| and having nonrotatably secured thereto a block 42 carrying a pivoted pawl 43 adapted to engage with internal ratchet teeth 44 on the drum.

The operation of the form of the invention just described is as follows:

To raise the blind the handle 4| is rotated in a clockwise direction. This causes the pawl 43 to engage with the ratchet teeth 44 and rotate the drum 3 I. The tape 23 is then wound on the drum, thus drawing'up the tapes 24 and 25. This elevates the lift bar 23 which carries with it the slats 23. When the blind is raised to the desired position the handle is released and will return to neutral position, as shown in the drawings. The action of the clutch block 32 on the tape 23 prevents the return of the lift bar and slats to lowered position until the tape is released by pressure on the push-button 38. The use of the ratchet is to prevent the operator from rotating the drum in a counterclockwise direction which would resuit in slack in theftape 28 and consequent kinking or buckling of thetape.

The modified form of the raising and lowering mechanism as illustrated in Figures 6 to 12 will now be described.

In its broad concept, this form of the invention operates upon the same broad principles as the previously described form of the invention.

Asshown in Figure 6, this form of the invention includes a housing construction generally indicated at 45, which is adapted to be formed from a preformed blank in a manner which will be subsequently described. housing is arranged to suitably support the associatedinstmmentalities of the mechanism, and is also arranged to be associated with a fabricated guide member 43 which may be secured'in any suitable manner to the window frame.

As shown, the guide comprises a web porv.tion 41 having a V-shaped trough 43 along one jedge defined by diverging members 43 and 53. .Alo'ng the opposite edge of the guide, the web is .fprm'ed'to define a T-shaped foot 3| which may be provided with suitable holes therethrough by n s nf which the guide may be secured to the window frame so as to extend vertically therenions therein. It passes over a roller 26 at the along. The v-shaped trough 43 is arranged to receive the slat tnmnions therein for vertical movement in the same manner as the trunnions 22 are received into the channel bar guide It as previously described.

The housing 45 is a box-like structure comprising a main plate portion 52, front and rear walls 53 and 54 respectively and a side wall 55 is in spaced relation and parallel to the-main plate 52. The upper and lower edges of the front and rear walls are inclined and arranged to receive therein top and bottom cover plates 53 and 51 respectively which are similarly formed to permit their being interchanged.

Mounted in aligned openings 58 and 53 of the side wall 55 and base plate 52 respectively of the housing is a shaft 50 which is held against rotative movement in any suitable manner. In the present instance this shaft is provided at one end with a'head GI and is riveted or peened over at its other end as shown at 52.

Rotatably mounted on the shaft 33 is a winding reel 83 which is formed with a circumferentially extending channel or groove 84 which is adapted to have wound thereon in superposed layers the tape 28.

The reel 33 is maintained in spaced operative relationship relative to the wall 52 by means of a collar spacer which is disposed between the reel and the wall 52 surrounding the shaft 33.

Also, the reel is secured for simultaneous rotative movement to a helical worm gear 38.

Meshing with the worm gear 33 is a triple thread worm 31 which is fixedly secured to a shaft 33 extending at right angles relative to shaft 33 and having its ends rotatably supported in the front and rear walls 53 and 54 of the housing. One end of this shaft projects past the front wall of the housing and is formed with a polygonal end 33 adapted to receive an operating handle by means of which the shaft may be rotated.

From experience, it has been found that with the ordinary type of worm and worm wheel drive, for the purpose described herein, they do not give a practical operating speed, when the pitch of the worm and gear are so selected as to prevent reverse drive of the mechanism due to the weight of the blind. In order to overcome this difficulty, the present invention resorts to the novel expedient of providing a worm and worm gear drive in which the angle of worm lead is greater than the helix angle of the worm gear. Such a design is contrary to good gear design and in fact results in an inefficient power transmitting arrangement. This arrangement, due to the fact that it is operated at low speed, sacrifices some of the advantages of efllcient operation, but does result'in eflecting the desirable advantage of setting up suificient friction between the meshing teeth of the worm and the teeth of the worm gear to prevent reverse drive and at the same time enable the use of such pitch as will enable the attaining of a practical speed of operation.

In the present arrangement, the guide strip is cut out'to form an opening 13, as shown in Fig. "I

in the web portion 41 and foot portion 5| of the guide strip of suflicient size to enable the insertion of the base plate 52 of the housing into the opening beneath the guide until the rear wall 54 of the housing abuts the guide member. In this position, the reel 33 projects past the web portion 41 of the guide, as shown in Fig. 8 sufilciently to bring the strip 28 along the rear side of web 41.

The strip 28 is connected at its uppermost end to which controlled by the flexible connection strip 2.. It

will be obvious that if some means were not provided, the reel could be continued in its lowering movement and the strip 20 would be wound on the reel in the opposite direction with the result that it would become kinked and otherwise damaged.

In order toguard against such contingency, a latch member II is pivotally suppored at one end of a pivot stud 12 which is anchored to the base plate of the housing. The free end of the latch member projects into the channel it on the reel and is provided with a spring 11 which normally tends to rotate the latch in a clockwise direction about its pivot as viewed'in Fig. 9.

The base of the channel 64 is provided with an opening ll which is adapted to receive the end .of the latch arm therein, when there is no strip 28 wound on the reel. Thus, when the reel is being rotated in a counterclockwise direction as shown in Fig. 9, which is the direction for lowering the blind, and the tape has been completely unwound, the latchpasses into the open ing- 14 and prevents further movement ofthe reel in lowering direction. Of course, with this arrangement the flexible connection to the lift bar should be or proper length to assure that the tape 28 is unwound when the lift bar reaches the bottom of the window.

Although the latch Ii will prevent further low- ,ering movement under these conditions of the reel $3, the reel is free to be moved in the opposite or raising direction. As the reel is thus moved in raising direction, the tape 2| will be wound on the reel and since this tape covers the opening II, the tape will prevententrance of the latch into the opening during raising movement of the blind.

Referring to Figure 11, the preformed blank from which the housing is fabricated, shown. The various wall sections of the housing are integrally formed and provided with openings for receiving the shafts Cl and it. The base plate section contains the opening I! and also I an opening 16 which may be utilized for mounting the pivot I! of the latching arm II. In addition screw holes It are also provided in the base plate section. The front and end wall sections 53 and 54 are provided with openings 11 and II which are adapted in the finished housing for receiving the ends of shaft 68. Likewise, the side wall section II is provided with openlugs-I8.

This blank may be cut to the shape shown and provided with the various openings to form a standard preformed blank. This blank is adapted to be deformed into a housing suitable for right or left hand mounting simply by bending the various sections in appropriate direction.

It is desirable to provide the base plate with longitudinally extending corrugations as shown at II, and these" corrugations may be stampedor These cables will be carried downotherwise formed in the base plate portion, the material being upset in proper direction depending upon whether the blank is to form a right or left hand housing.

with the blank as just described, it will not make any difference whether it is formed into a right or left hand housing. In either case, the

apertures 5| and 59 will be properly aligned as will also the apertures 11 and It.

The rear wall section 54 is provided with diverging leg portions and BI having deflective ends 82 and 83 to provide feet for welding or otherwise securing these leg portions to the base plate 52, when the housing is completely formed. These leg portions provide a suitable space so that the reel 83 may project from the housing as shown. The top and bottom cover plates are stamped or otherwise formed from a single sheet of material and are preferably provided with peripheral edge flanges 84 which are adapted to slidably flt within the walls of the housing and hold the covers in position.

In Figures 13 and 14 there other form of winding reel for raising and lowering .a Venetian blind.

This form of the invention comprises, as in the previously described arrangement, a suitable housing for the reel operating mechanism which may be, though not necessarily constructed from a preformed blank as described above.

The winding reel is mounted on a shaft 85 which is rotatably mounted in the housing walls. This shaft may be extended at one end to in tegrally form an operating handle 86, or if desired, this handle may bev separately formed and adapted in any suitable manner for removably securing to the shaft.

' Instead of providing similar end flanges on the winding reel, one end flange of the reel is deflned by a latch wheel 81 having a plurality of teeth 8| arranged around its circumference. These teeth arecooperatively associated with a tooth .8! carried by a latch member 90, this member being supported for raisingand lowering guided movements on spaced guide pins 9i and 92. The pins are each anchored at one end in the ad- Jacent wall of the housing and respectively pro- Ject into guide slots II and 94. The latch member is therefore free to move upwardly and downwardly to move the tooth 89 out of and into meshing relation with the teeth on the latch wheel, the latch member being actuated downwardly by the action of gravity thereon.

The teeth 88 are correspondingly each provided with a-' curved abutment edge on one side as shown at II, this edge being arranged to interfittingly engage with a mating surface 06 on the f of thesurface 9l'of each tooth against the surface 08 causes the latch member to be raised, wherein the tooth 80 is moved out of its cooperative relation with the teeth on the latch wheel.

with the latch member moved to unlatched position, the reel is then 'free to be moved in either direction, and so long as the reel is operated at a relatively fast speed the latch member will be prevented by the teeth from moving,

is illustrated an to latching position. However, as soon as movement of the reel is terminated the latch member under the action of gravity is moved to latching position wherein the tooth 89 provides a stop for preventing movement of the latch wheel and By the use of this mechanism, the blind mayreadily and easily be moved from one position of adjustment to another. If the blind is to be raised, the crank or handle is merely moved in the raising direction until the blind is at the desired height, and as soon as the crank movement is stopped, the latch will operate to positively hold the blind. To lower the blind, the crank is initially moved in 9. raising direction to cause the latch to be released, whereupon the crank is actuated in the other direction to lower the blind to the desiredposition. As soon as the crank movement is stopped the latch again operates to positively hold the blind at its new position of adjustment.

From the foregoing description, it will be apparent that the present invention provides improved means for raising and lowering a blind; which embodies novel means for automatically maintaining the blind in adjusted position and at the same time enables it to be readily and easily raised and lowered to other positions of adjustment; which embodies a novel irreversible worm gear drive; which is provided with novel means ing as desired from a standard preformed blank.

It is of course to be understood that although I have described in detail several embodiments of my invention, the invention is not to be thus limited but only insofar as defined by the sco and spirit of the appended claims. I

I claim:

.1. In a device of the character described, a reel mechanism, a housing for said mechanism formed from a flat blank, said blank having sections so arranged that the blank may be deformed in one direction to effect a right-hand housing and in an opposite direction to eii'ect a left-hand horasing.

2. In a device of the character described, a reel mechanism, a housing for said mechanism, said housing being formed from a flat blank deformable to adapt it for right and left-hand mounting, and a closure member adapted to be associated with said housing irrespective of whether it is deformed for right or left-hand mounting,

3. In a device of the character described, a reel mechanism, and a housing for said mechanism comprising a preformed flat blank having a plurality of integrally joined sections, certain of said sections containing apertures to be brought into alignment upon the deformation of said blank to form a right or left-hand mountable housing, as desired.

FRED E. LAWSON. 

